The present invention relates to a vehicle having a magnetic drive for conveying a variety of tool heads over ferromagnetic surfaces to accommodate the treating of the surfaces (e.g. cleaning or painting). In a particular CHASSIS construction, a number of laminated, permanent magnet wheels are mounted to independent suspensions at each axle to convey a drive CHASSIS and tool head over the support substrate.
Maintenance activities for a variety of ferromagnetic or metal surfaces, such as found in ships and at the interior and exterior surfaces of storage tanks, are normally performed manually after a system of scaffolds and other work supports are erected. The manual nature of such operations and the extensive setup and disassembly activities are very time consuming and economically costly
A variety of magnetic vehicles have been developed to reduce the foregoing setup and disassembly activities. Examples of various of these vehicles are shown a U.S. Pat. Nos. 3,682,265; 3,777,834; 3,960,229; 4,789,037; 4,890,567; and 5,285,601. Common to all of these vehicles is a track driven vehicle which contains a series of either electromagnets or permanent magnets mounted to the tracks or to the vehicle. The magnets rotate with the tracks and progressively engage and disengage the work surface. A variety of metal surface conditioning tool heads are also fitted to the vehicles.
Although track drives provide a number of magnet elements which simultaneously contact the support surface to enhance the magnetic attraction, a variety of shortcomings exist. The vehicles frequently include separate drive assemblies at each track which increases the cost and weight of the vehicle. Reduced magnetic attraction is also experienced when working on surfaces having tight curvatures or surface transitions as the magnets span the curvatures and transitions with reduced surface contact. Difficulties also frequently occur in steering or maneuvering the separate tracks. Steering adjustments are most commonly made through independent braking and speed adjustments to the tracks.
In appreciation of the foregoing deficiencies of known magnetic vehicles, the wheeled vehicle of the invention was developed to provide a light weight chassis which is driven by a single motor and supported from a number of permanent magnet wheels. An articulating chassis and independent, resilient suspensions support each of the wheels to optimize wheel contact with the surface and especially upon encountering elevation changes. The chassis is remotely steered and able to support a variety of tool heads at either end of the chassis.